That page is linked to from the Metropolitan Museum of Art’s press release about the images being available for use.
I found the press release via this Engadget post about the news (that doesn’t discuss how to actually go about getting the images at all).
The article and the press release both indicate that there are over 375,000 images available, so I find it odd that when you actually drill down to the collection (the link that I began this post with) and you filter by Public Domain, there are only “200,128 results out of 441,174 records” available, which smells like some press release inflation to me and some lack of diligence by everyone ingesting & regurgitating the press release.
However, more importantly to me, one of the people who first got paid for blogging on this here internets (back in my day…), I find it supremely irritating that in the spirit of keeping the reader’s eyes on our ads and on our site, there is no clear, easy to find path to find out exactly how to use these images in Engadget or any other “news coverage” of this that I’ve seen. Everyone just lazily throws it out there without any useful linking as if it were a newspaper, and that, my friends, is why blogging has become more marginalized and less powerful. We gave up our super-powers for ad money. #seewhatididthere